Conductor roll for apparatus for electrolytically treating strip



INVENTOR.

CLARENCE J. KLEIN y ATTORNEY Sept. 15, 1953 c. J. KLEIN CONDUCTOR ROLL FOR APPARATUS FOR ELECTROLYTICALLY TREATNG STRIP Filed Aug. 4, 1949 Patented Sept. '15, 1953 NITED 2,652,4itl

CONDUCTOR ROLL FOR APPARATUS FOR ELECTROLYTICALLY TREATING STRIP Clarence J. Klein, Weirton, W. Va, assignor to National Steel Corporation, a corporation of Delaware Application August 4, 1949, Serial No. 108,607

3 Claims. (Cl. 19ll1) The present invention relates to improvements in apparatus for electrolytically treating strip material and provides an improved conductor roll particularly adapted for use in such an apparatus to connect the strip to a source of electric current.

In electrolytically treating moving strip, the strip is passed across a bath of electrolyte solution containing an electrode connected to a source of electric current. A rotatable conductor roll engages the moving strip and is connected to the source of electric current to complete the electric circuit through a portion of the strip. The else-- trolytic treatment to which the strip is subjected may be electrolytic cleaning where the strip is cathodic or anodic, electrolytic pickling, or else troplating. The present invention is primarily concerned with and will be described in connection with the progressive electroplating of a moving steel. strip with tin where the strip is made iodic, although the present invention is not its: to these metals or to electroplating.

object of the present invention is to proimproved apparatus for electrolytically ating strip material that includes a novel conductor roll for connecting the strip to a source of electric current.

promote such a conductor roll which will offer a in'uiinum resistance to the flow of electric currt to the strip.

Another object of the present invention is to provide such a conductor roll which combines maximum strength and resistance to attack by the electrolyte with minimum resistance to the flow of electric current to the strip.

These and other objects and advantages will become more apparent when considering the fol" lowing description, taken with the accompanying drawings in which:

Figure 1V is a view in elevation of apparatus embodying the principles of the present invention;

and, H D

Figure 2 is an enlarged, fragmentary longitudinai section of a portion of the apparatus of Fig:- ure 1.

In electroplating lines, the strip is supported and progressively moved across the electroplating cell which contains one or more anodes sub- 12" in the electroplating solution of the cell. The electroplating cell may be of any suitable t may be of the type shown and described in Patent No. 2,399,254 issued to Rieger et al. on April 30, 1946. The anodes are connected to a generator or other source of electric current. In

other object of the present invention is to 2 present day practice, a low voltage, high amperage current on the order of, for example, 12 volts is used to electroplate steel strip with tin.

Referring to the drawings, the strip S which is supported and propelled along a predetermined path through the electroplating line by means of power-actuated rolls of the type customarily used in steel mills, or in any suitable manner, progressively passes between an upper conductor roll it and a lower back-up roll ll which holds the strip S in contact with the conductor roll it. Both rolls ill and II are rotatably mounted in the frame i2. The conductor roll it includes an elongated, hollow, substantially cylindrical body portion I i having a cylindrical external surface it: which contacts the strip S. The body portion it is formed of conductive metal and is preferably formed of a steel alloy or other metal which is relatively strong and which is resistant to attack by the electroplating solution. Each end of the body it is mounted on a casing or sleeve it which, preferably, is formed of steel to provi e the maximum strength and life for the conductor roll. Each sleeve It is rotatably mounted in a corresponding bearing i8 carried by the frame l2 so that the conductor roll is free to rotate about the longitudinal axis of the roll. On the outer end of one sleeve it, there is mounted a pulley 59 adapted to be connected through a belt to a motor (not shown) for rotating the conductor roll at the same peripheral speed as the strip. The pulley may be eliminated, but it is preferred to rotate the conductor roll to prevent slippage between the conductor roll and the strip S.

The conductor roll it includes means for connecting the body portion it to a source of electroplating current. An elongated copper member 2i an enlarged end portion 2? inside of the strip contacting body portion Hi. The enlarged end of member 25 has a threaded external surface threadedly engaging a threaded internal surface of the body portion It at 23. With this threaded connection at the member 21 and the strip contacting body portion hi are in electrical con tact with each other throughout a relatively great area, and the connection between these parts is tight. The copper member 2i includes a portion 23 of reduced size which extends through the steel sleeve it with an outer end portion i i outside of the sleeve. On the end portion 2d of member 2 i, there is mounted a copper slip ring which is engaged by a plurality of brushes 25 supported by part of the frame l2 and connected to the source of electroplating current (not shown). With this arrangement, the current 23 is larger than the maximum cross sectional area of the copper member 2!; Preferably, each end of the conductor roll is connected to a source of electric current to provide more uniform distribution of current throughout the length of .the. body portion [4 and across the stri The sleeves [6 at opposite ends of the strip contacting body portion l4 are formed ofsteel or other metal of relatively lower conductivity than copper which provides the maximum strength. With the slip ring mounted on the outer end of the copper member 3i, the electric current flows through the copper memberZj which offers a relatively lower resistance and ther is less voltage drop than there would be if the slip ring were mounted on the outer endof the sleeve which has arelatively lower conductivity. This is particularly important where low voltage current is used as is customary in present day tin electroplating lines. In addition, the steel sleeve it has a relatively high resistance to attack by the electroplating solution. Forvarious reasons, such the strip dragging solutionoutof the electr ating cell, electroplating solution comes in con .ct with the body portion lland sleeve is? so that it is important that these members be resistant to attack by the solution to increase the life of conductor roll. The steel sleeve [band th body portion l4 cover and protect the copper member 2 I which would be readily eroded by the electroplating solution.

' Beneath the conductor roll It, there is rotatably mounted a back-up roll II, the backup roll I l includes a metal shaft 23 rotatably mounted at each end in a bearing 29 carried by the frame I2; The shaft is covered with a protective layer of rubber 39, and the bearings ZBresiliently urged upwardly to press the back-up 1-011 and the strip S upwardly againstfthe conductor roll Iii. As shown more clearly'in Figure 2 each bearing 253 is urged upwardly by aspring 3|. which is, in turn, mounted on the upper end of a pin EZ-carried by the frame l2. The pin 32 is threaded for vertical adjustment for varying the compression of the spring 3| andthe pressure of roll ll upwardly against conductor roll ill. the back-up roll H, there is preferably mounted apulley 33 or othersuitabl means for connecting the roll to a motor (not shown) for rotating the rollat a peripheral speed the same as the lineal speed atwhich the strip moves along its path through the electroplating line. Preferably, both rolls l and II are rotated by means of pulleys wand 33 so that the surfaces of the rolls are moving at the same lineal speed as the strip so that there is no' slippage between the rolls and the strip.

In the present conductor roll, there is a minimum of resistance to the flow of electric current between the slip ring 25 and the body portion [4. The member 2| has" relatively low electrical resistance and the tight fitting threads at 23 provide' an electrical connection of relatively large area that offers aminimum resistance to flow of electric current between members I A and 2|. The supporting sleeve 0r shaft provides maximum On theouter end of strength and protects the copper member 2l against attack by the electrolyte from the electrolytic cell which increases the life of the roll. The roll I0 is relatively easily constructed which lowers its cost, Reducing the initial cost and the maintenance cost of conductor rolls is important as a singleelectroplating line willcontain, for example, twenty six of these rolls.

I claim:

1. A conductor roll for making electrical contact with andconducting electrical current to a moving strip comprising an elongated integral tubular body member formed of a conductive metalhaving anv internal substantially cylindrical surface and an external substantially cylindrical surface formaking electrical contact with thesur fa ceof the moving strip, the internal surface of the body member including a threaded surface. portion, supporting means mounted at the ends of the body member for rotatably supporting the bodymember for rotationabout its longitudinal axis, the supporting means including a supporting. member. at one endof the body member having a longitudinal boreconcentric with the longitudinal-"axis of the body member, and an integral electrical current conductor mem,- ber formed of conductive metal having a relatively lower electrical resistance than the supporting member for connecting the, body member toa sourc of electrical current, the integral conductor member including'jafirst portion extending outside the supp-ortin'gfmember and adapted to be connected to a sourceof electrical current, a second portion extending through the boreof the supporting member and anenlarged portion ex:- tending into one end of the body member, the enlarged portion including an external threaded substantially cylindrical surfac havinga diameter substantially. equal to the diameter of the threaded surface portion of the internal surface of the body member, and the external threaded surface on'the enlarged portion of the integral conductor member threadedly engaging the threaded surface portion of the body member to form a mechanical connection and a low resistance electrical connection between the integral conductor member and the bodymember.

2. A conductor roll for making electrical contact with. and conducting. electrical currentto a moving strip comprising an elongated integral tubular body member formed of a conductive metal having an internal substantially cylindrical surface and anexternal substantially cylindrical surface for making electrical contact with the surface of the moving strip, the internal sub,- stantially cylindrical surface including a threaded surface portion spaced from one end of the body member and an increased diameter substantially cylindrical surface portion between the threaded surface portion and the one end of the body member, an integral electrical current conductor member for providing a path of lowelectrical resistance from a source of electrical current to the external cylindrical surface of the body member, the integral conductor member including an enlarged substantially cylindrical end portion and a second substantially cylindrical portion having a diameter less than the diameter of the enlarged end portion: extending axially of one end of the enlarged portion, an external threaded surface on the enlarged end portion ofthe conductor member, the external threaded surface of the conductor member having a diameter substantially equal to vthediameter of the threaded surface portion ofthebodyv member, the conductor member extending into the one end of the body member with the external threaded surface on its enlarged end threadedly engaging the threaded surface portion of the internal surface of the body member, and supporting means mounted at the ends of the body member for rotatably supporting the body member for rotation about its longitudinal axis, the supporting means including a rotatably mounted sleeve member extending over the second portion of the conductor member and within the increased diameter portion of the body member, the integral conductor member having a relatively lower electrical resistance than the sleeve member.

3. A conductor roll for making electrical contact with and conducting electrical current to a moving strip comprising an elongated integral tubular body member formed of a conductive metal having an internal cylindrical surface and an external cylindrical surface for making electrical contact with the surface of the moving strip, the internal cylindrical surface including a threaded portion spaced from each end of the body member and an increased diameter portion between each threaded portion and an end of the body member, an integral electrical current conductor member at each end of the body member for providing a path of low electrical resistance from a source of electrical current to the external cylindrical surface of the body member, each of the integral conductor members including an enlarged cylindrical end portion and a second cylindrical portion of a diameter less than the diameter of the end portion extending axially of one end of the enlarged end portion, an external threaded surface on the enlarged end portion of the conductor members, the external threaded surface on the conductor members having a length and diameter substantially equal to the length and diameter of the threaded portion of the internal surface of the body member, each conductor member extending into an end of the tubular body member with the external threaded surface of its enlarged end portion threadedly engaging the threaded portion of the internal surface of the body member and with its second portion extending through the region of the increased diameter portion of the internal surface of the body member in concentric relation therewith and terminating beyond the end of the body member, a rotatably mounted cylindrical sleeve member positioned at each end 0; the body member for rotatably supporting the body member for rotation about its longitudinal axis, each of the sleeve members having a cylindrical bore of a diameter substantially equal to the diameter of the second portion of the conductor member and including an enlarged end portion provided with an external cylindrical surface of a diameter substantially equal to the diameter of the increased diameter portion of the internal surface of the body member, the enlarged end portion of each sleeve member being mounted in an end of the body member with the second portion of the conductor member passing through the cylindrical bore of the sleeve member, the external cylindrical surface of the sleeve member contacting the increased diameter portion of the body member and the end of the enlarged portion of the sleeve member abutting the one end of the enlarged portion of the conductor member, and a third portion extending integrally from the second portion of the conductor member outwardly beyond the sleeve member and adapted to be connected to a source of electrical current, the conductor member being formed of a conductive material having a lower electrical resistance than the sleeve members.

CLARENCE J. KLEIN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,064,764 Parker June 17, 1913 2,217,015 Gurwick et al. Oct. 8, 1940 2,266,347 Watson Dec. 16, 1941 2,267,209 Morando Dec. 23, 1941 2,439,858 Muddiman Apr. 20, 1948 2,446,548 Nachtman Aug. 10, 1948 2,513,515 Power July 4, 1950 2,526,312 Winterhalter Oct. 17, 1950 

